
Cerys D. answered 03/24/20
High School Math Teacher
The first thing we want to do when we solve by elimination is to line up the variables:
2x-4y=10
-2x+6y=-4
Now, we think about if we add or subtract both equations together, can we have one of the variables be equal to 0? Our goal is to have a variable be eliminated.
In this case, we have 2x and -2x in the two equations. If we add these together, -2x+2x=0x
When we add both equations together we get:
2x-4y=10
+(-2x+6y=-4)
= 0x+2y=6
Now solve for y:
2y=6
y=3 (divide both sides by 2)
Now we have our y value, but a solution to a system of equations requires x and y. Now we can plug in our y value into one of the original equations. I will choose the first equation.
2x-4y=10
2x-4(3)=10
2x-12=10
2x=22 (add 12 to both sides)
x=11 (divide both sides by 2)
So we get:
x=11 and y=3